Method and means of conveyance of solid matter in pieces or particles

Abstract

Method and means of conveyance for solid material, f.ex. tree trunks (6) or bark, whereby the solid material is conveyed with parallel, oblong transfer elements (4) moving back and forth in transfer direction. A larger part of the surface of the transfer elements (4) is moving forward at a time than moving backward. The speed of the return motion of the transfer elements is higher than that of the feed motion of the transfer elements. Transfer elements (4) at sides of the conveyor have been inclined on their longitudinal axis so that they slope towards the center of the conveyor. In this way the friction force between the particles (6) of the material to be conveyed is increased and the friction force between the material (6) to be conveyed and the transfer elements (4) is decreased.

I claim: 
     
       1. A method of conveying pieces of material comprising the steps of: placing said pieces of material onto a support surface area of a conveyor formed of a plurality of parallel oblong transfer elements;   simultaneously moving a predetermined number of said transfer elements in a forward motion and a predetermined number of said transfer elements in a return motion along a line parallel to a conveying direction such that said support surface area of said conveyor includes a forward moving surface area and a return moving surface area, wherein at any predetermined period of time, said forward moving surface area is in contact with said pieces of material and is larger than said return moving surface area, and wherein the speed of said return motion is higher than the speed of the forward motion;   urging said pieces of material through said conveyor wherein a first frictional force between each of the pieces is increased as a result of positioning outermost transfer elements at an angle relative to a horizontal plane, said first frictional force being greater than a second frictional force existing between the pieces of material that are being conveyed and the transfer elements.   
     
     
       2. A means for conveying pieces of material comprising: frame means;   a plurality of oblong shaped transfer elements positioned substantially parallel to each other along a conveying direction on said frame means to form a conveyor with a predetermined surface area, said transfer elements being movable in a forward and return motion along a line parallel to said conveying direction such that said conveyor has a forward moving surface area and a return moving surface area at any particular period of time; said forward moving surface area being in contact with said pieces of material and being larger than said return moving surface area at any particular period of time;   means for moving each of said plurality of transfer elements at a return speed of movement that is greater than a forward speed of movement; and   outermost transfer elements of said conveyor being inclined relative to a horizontal plane such that said outermost transfer elements slope towards a center of said conveyor.   
     
     
       3. A means for conveying pieces of material as set forth in claim 2, wherein transfer elements on either side of a center region of said conveyor are positioned at an angle of inclination relative to said horizontal plane such that said conveyor has a substantially semi-circular cross-section. 
     
     
       4. A means for conveying pieces of material as set forth in claim 2, wherein said plurality of transfer elements are positioned to receive a substantial portion of a primary contact surface area of each of said pieces of material. 
     
     
       5. A means for conveying pieces of material as set forth in claim 2, further comprising a drum means for debarking tree trunks positioned adjacent said conveyor, said drum means having a revolving feed opening, said feed opening having a bottom form conforming to a bottom form of said transfer elements of said conveyor, said transfer elements extending across an end face of said drum means at said feed opening. 
     
     
       6. A means for conveying pieces of material as set forth in claim 2, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       7. A means for conveying pieces of material as set forth in claim 3, wherein said plurality of transfer elements are positioned to receive a substantial portion of a primary contact surface area of each of said pieces of material. 
     
     
       8. A means for conveying pieces of material as set forth in claim 3, further comprising a drum means for debarking tree trunks positioned adjacent said conveyor, said drum means having a revolving feed opening, said feed opening having a bottom form conforming to a bottom form of said transfer elements of said conveyor, said transfer elements extending across an end face of said drum means at said feed opening. 
     
     
       9. A means for conveying pieces of material as set forth in claim 4, further comprising a drum means for debarking tree trunks positioned adjacent said conveyor, said drum means having a revolving feed opening, said feed opening having a bottom form conforming to a bottom form of said transfer elements of said conveyor, said transfer elements extending across an end face of said drum means at said feed opening. 
     
     
       10. A means for conveying pieces of material as set forth in claim 7, further comprising a drum means for debarking tree trunks positioned adjacent said conveyor, said drum means having a revolving feed opening, said feed opening having a bottom form conforming to a bottom form of said transfer elements of said conveyor, said transfer elements extending across an end face of said drum means at said feed opening. 
     
     
       11. A means for conveying pieces of material as set forth in claim 3, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       12. A means for conveying pieces of material as set forth in claim 4, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       13. A means for conveying pieces of material as set forth in claim 5, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       14. A means for conveying pieces of material as set forth in claim 7, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       15. A means for conveying pieces of material as set forth in claim 8, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       16. A means for conveying pieces of material as set forth in claim 9, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed. 
     
     
       17. A means for conveying pieces of material as set forth in claim 10, wherein said plurality of transfer elements include transfer surfaces, said transfer surfaces being arranged parallel to said conveying direction, said transfer surfaces having a frictional surface for creating a feeding frictional force by which said pieces of material are conveyed.